I am looking to build a thermometer to measure temperatures at different depths in a lake in reel time on an LCD. As many of you are aware there are tons of thermometer type application/circuit examples on the net. I'm pretty sure the basic design will be battery powered and contain a temp probe on a spool of wire which i will send out to specific depths and take a reading (would love a wireless application but the whole sonar thing might be a bit too complex). This is more than likely a one-time application for something that is really expensive to buy off the shelf (if you can find one). My goals are to come up with a cheap, easily reproduced custom solution.

The problem of course is that i'm a total newbie. I've read several of the projects people have posted, but i still find myself missing some of the critical basic info i need. Where should i start with circuits and programing chips? what microchip should i use? Is there a book i should buy, an online tutorial? I am competent with a soldering iron, and have some decent understanding on electronics etc. I am simply looking to acquire enough knowledge to do this project myself.

i here ya, i'm just concerned about bringing a laptop on a boat! Then i have to power the laptop as well, which would be irritating

I have never done any work with PDAs but most of them have a way of reading serial data, that might be another way that you could have something inexpensive to record and display your data. I have seen some of the older Palm PDAs going for $20 at some of the discount stores.

Yeah, I have one such Palm 7x that isn't getting any use. If it werent such a pain to develop in the Palm OS, I might use it more

I heard the same thing about programming those things... It would be cool to have a data acquisition program or something on one though. I wonder if the pocket PC devices would be easy to program for something like that?